commit fba9e856666b249fc476bd5fce2a1c55e1bbfa7a
Author: klein panic <kleinpanice@proton.me>
Date:   Sun Jan 26 04:11:18 2025 -0500

    first commit

diff --git a/vimwiki-markdown-preview.sh b/vimwiki-markdown-preview.sh
new file mode 100755
index 0000000..049c333
--- /dev/null
+++ b/vimwiki-markdown-preview.sh
@@ -0,0 +1,573 @@
+#!/usr/bin/env bash
+
+# ============================
+# Exit Status Codes
+# ============================
+EXIT_SUCCESS=0
+EXIT_FAILURE=1
+EXIT_DEPENDENCY=2
+EXIT_CONVERSION=3
+
+# ============================
+# Shell Options
+# ============================
+# Exit immediately if a command exits with a non-zero status,
+# Treat unset variables as an error,
+# Prevent errors in a pipeline from being masked
+set -euo pipefail
+
+# ============================
+# Color Definitions
+# ============================
+RESET='\033[0m'          # No Color
+BOLD='\033[1m'
+
+# Regular Colors
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[0;33m'
+BLUE='\033[0;34m'
+CYAN='\033[0;36m'
+
+# ============================
+# Configuration Constants
+# ============================
+
+# Absolute paths ensure the script can be run from any directory
+SOURCE_DIR="$HOME/vimwiki"                   # Source Vimwiki directory
+TEMP_DIR="/tmp/vimwikihtml"                  # Temporary HTML output directory
+CSS_FILE="$HOME/.local/share/nvim/style.css" # Path to the CSS file for styling
+CONCURRENT_JOBS=4                            # Number of concurrent pandoc processes
+LOG_FILE="$TEMP_DIR/conversion.log"          # Log file to track conversions
+ERROR_LOG_FILE="$TEMP_DIR/error.log"         # Log file to track errors
+VERSION="1.0.0"                               # Script version
+
+# ============================
+# Dependencies
+# ============================
+
+DEPENDENCIES=("pandoc" "sed" "qutebrowser" "find" "rsync" "grep" "mkdir" "basename" "diff")
+
+# ============================
+# Logging Functions
+# ============================
+
+# Function to log INFO messages
+log_info() {
+    local message="$1"
+    echo -e "${BLUE}[INFO]${RESET} $message"
+    echo "[INFO] $(date +"%Y-%m-%d %H:%M:%S") - $message" >> "$LOG_FILE"
+}
+
+# Function to log SUCCESS messages
+log_success() {
+    local message="$1"
+    echo -e "${GREEN}[SUCCESS]${RESET} $message"
+    echo "[SUCCESS] $(date +"%Y-%m-%d %H:%M:%S") - $message" >> "$LOG_FILE"
+}
+
+# Function to log WARNING messages
+log_warning() {
+    local message="$1"
+    echo -e "${YELLOW}[WARNING]${RESET} $message"
+    echo "[WARNING] $(date +"%Y-%m-%d %H:%M:%S") - $message" >> "$LOG_FILE"
+}
+
+# Function to log ERROR messages
+log_error() {
+    local message="$1"
+    echo -e "${RED}[ERROR]${RESET} $message" | tee -a "$ERROR_LOG_FILE"
+    echo "[ERROR] $(date +"%Y-%m-%d %H:%M:%S") - $message" >> "$ERROR_LOG_FILE"
+}
+
+# Function to handle errors with context and exit with specific code
+handle_error() {
+    local message="$1"
+    local exit_code="${2:-$EXIT_FAILURE}"
+    local func="${FUNCNAME[1]}"
+    local line="${BASH_LINENO[0]}"
+    log_error "In function '$func' at line $line: $message"
+    exit "$exit_code"
+}
+
+# ============================
+# Filename Validation Function
+# ============================
+
+# Function to check if a filename contains only allowed characters
+is_valid_filename() {
+    local filename="$1"
+    if [[ "$filename" =~ ^[A-Za-z0-9._-]+$ ]]; then
+        return 0
+    else
+        return 1
+    fi
+}
+
+# ============================
+# Bash Availability Check
+# ============================
+
+# Function to ensure that Bash is available
+check_bash() {
+    if ! command -v bash &>/dev/null; then
+        echo -e "${RED}[ERROR]${RESET} Bash is not installed. Please install Bash to run this script."
+        exit "$EXIT_FAILURE"
+    fi
+}
+
+# ============================
+# Path Validation Function
+# ============================
+
+# Function to validate and sanitize input paths
+validate_paths() {
+    log_info "Validating input paths..."
+
+    # Check that SOURCE_DIR is an absolute path
+    if [[ "$SOURCE_DIR" != /* ]]; then
+        handle_error "SOURCE_DIR ('$SOURCE_DIR') is not an absolute path." "$EXIT_FAILURE"
+    fi
+
+    # Check that TEMP_DIR is an absolute path and under /tmp
+    if [[ "$TEMP_DIR" != /tmp/* ]]; then
+        handle_error "TEMP_DIR ('$TEMP_DIR') must be under /tmp." "$EXIT_FAILURE"
+    fi
+
+    # Check that SOURCE_DIR exists and is a directory
+    if [[ ! -d "$SOURCE_DIR" ]]; then
+        handle_error "SOURCE_DIR ('$SOURCE_DIR') does not exist or is not a directory." "$EXIT_FAILURE"
+    fi
+
+    # Check if TEMP_DIR exists; if not, it will be created later
+    # If it exists, ensure it's a directory
+    if [[ -e "$TEMP_DIR" && ! -d "$TEMP_DIR" ]]; then
+        handle_error "TEMP_DIR ('$TEMP_DIR') exists but is not a directory." "$EXIT_FAILURE"
+    fi
+
+    log_success "Input paths are valid."
+}
+
+# ============================
+# Function Definitions
+# ============================
+
+# Function to check if all dependencies are installed
+check_dependencies() {
+    log_info "Checking for required dependencies..."
+    local missing_dependencies=()
+
+    for cmd in "${DEPENDENCIES[@]}"; do
+        if ! command -v "$cmd" &>/dev/null; then
+            missing_dependencies+=("$cmd")
+        fi
+    done
+
+    if [[ ${#missing_dependencies[@]} -ne 0 ]]; then
+        for cmd in "${missing_dependencies[@]}"; do
+            handle_error "Dependency '$cmd' is not installed. Please install it and retry." "$EXIT_DEPENDENCY"
+        done
+    fi
+
+    log_success "All dependencies are satisfied."
+}
+
+# Function to extract the title from Markdown using YAML frontmatter or fallback to filename
+extract_title() {
+    local md_file="$1"
+    # Attempt to extract title from YAML frontmatter
+    local title
+    title=$(grep -m1 '^title:' "$md_file" | sed 's/title: //') || true
+    if [[ -z "$title" ]]; then
+        # If no title found, use the filename without extension
+        title=$(basename "$md_file" .md.old)
+    fi
+    echo "$title"
+}
+
+# Function to convert a single Markdown file to HTML atomically
+convert_md_to_html() {
+    local md_old_file="$1"  # Path to the .md.old file
+    # Determine the relative path from TEMP_DIR
+    local relative_path="${md_old_file#$TEMP_DIR/}"
+    # Remove .md.old extension
+    relative_path="${relative_path%.md.old}"
+    # Determine the output HTML file path
+    local html_file="$TEMP_DIR/${relative_path}.html"
+    # Determine the temporary HTML file path
+    local temp_html_file="${html_file}.tmp"
+    # Create the necessary directories for the HTML file
+    mkdir -p "$(dirname "$html_file")"
+
+    # Extract the title for the HTML document
+    local title
+    title=$(extract_title "$md_old_file")
+
+    log_info "Converting '$md_old_file' to '$html_file'..."
+
+    # Use pandoc to convert Markdown to HTML with CSS and metadata
+    if [[ -f "$CSS_FILE" ]]; then
+        if ! pandoc -f markdown -s --css="$CSS_FILE" --metadata title="$title" "$md_old_file" -o "$temp_html_file"; then
+            handle_error "Failed to convert '$md_old_file' to HTML." "$EXIT_CONVERSION"
+        fi
+    else
+        log_warning "CSS file '$CSS_FILE' not found. Skipping CSS for '$md_old_file'."
+        if ! pandoc -f markdown -s --metadata title="$title" "$md_old_file" -o "$temp_html_file"; then
+            handle_error "Failed to convert '$md_old_file' to HTML." "$EXIT_CONVERSION"
+        fi
+    fi
+
+    # Debug: Print a snippet of the HTML file before running sed
+    log_info "Snippet before sed in '$temp_html_file':"
+    head -n 5 "$temp_html_file" || true
+    echo "..."
+
+    # Adjust internal href links:
+    # 1. Replace href="path/to/file.md.old" with href="path/to/file.html"
+    # 2. Replace href="path/to/file" with href="path/to/file.html" only if 'file' has no extension
+    log_info "Adjusting links in '$html_file'..."
+
+    # First, replace links ending with .md.old
+    if ! sed -i -E 's|(href=")([^"#:/]+(/[^"#:/]+)*)\.md\.old(")|\1\2.html\4|g' "$temp_html_file"; then
+        handle_error "Failed to adjust '.md.old' links in '$temp_html_file'." "$EXIT_CONVERSION"
+    fi
+
+    # Then, replace links without any extension
+    if ! sed -i -E 's|(href=")([^"#:/.]+(/[^"#:/.]+)*)(")|\1\2.html\4|g' "$temp_html_file"; then
+        handle_error "Failed to adjust extensionless links in '$temp_html_file'." "$EXIT_CONVERSION"
+    fi
+
+    # Adjust src attributes for images to prepend /tmp/vimwikihtml
+    log_info "Adjusting image paths in '$temp_html_file'..."
+    if ! sed -i -E 's|(<img[^>]*src=")(/[^"]*)(")|\1/tmp/vimwikihtml\2\3|g' "$temp_html_file"; then
+        handle_error "Failed to adjust image paths in '$temp_html_file'." "$EXIT_CONVERSION"
+    fi
+
+    # Move the temporary HTML file to the final destination atomically
+    mv "$temp_html_file" "$html_file"
+
+    # Debug: Print a snippet of the HTML file after running sed
+    log_info "Snippet after sed in '$html_file':"
+    head -n 5 "$html_file" || true
+    echo "..."
+
+    # Log the successful conversion
+    echo "$(date +"%Y-%m-%d %H:%M:%S") - Converted '$md_old_file' to '$html_file'." >> "$LOG_FILE"
+
+    log_success "Successfully converted '$md_old_file' to '$html_file'."
+}
+
+# Function to synchronize Markdown files and relevant assets to TEMP_DIR
+synchronize_markdown() {
+    log_info "Synchronizing Markdown files and assets to '$TEMP_DIR'..."
+
+    # Use rsync to copy only .md, .pdf, and image files, excluding unwanted directories and files
+    rsync -av --delete \
+        --exclude='*.html' \
+        --exclude='*.sh' \
+        --exclude='.git/' \
+        --exclude='.gitignore' \
+        --exclude='*.bak' \
+	--exclude='*.tex' \
+	--exclude='*.toc' \
+	--exclude='*.out' \
+        --include='*/' \
+        --include='*.md' \
+        --include='*.pdf' \
+        --include='*.png' \
+        --include='*.jpg' \
+        --include='*.jpeg' \
+        --include='*.gif' \
+        --exclude='*' \
+        "$SOURCE_DIR/" "$TEMP_DIR/" | grep '\.md$' || true
+
+    log_success "Synchronization completed."
+}
+
+# Function to rename .md files to .md.old in TEMP_DIR
+rename_md_files() {
+    log_info "Renaming new or modified .md files to .md.old in '$TEMP_DIR'..."
+
+    # Find all .md files in TEMP_DIR
+    find "$TEMP_DIR" -type f -name '*.md' | while IFS= read -r md_file; do
+        # Determine the corresponding .md.old file
+        md_old_file="${md_file}.old"
+
+        # Determine the source .md file
+        source_md="$SOURCE_DIR/${md_file#$TEMP_DIR/}"
+
+        # Check if the .md.old file exists
+        if [[ ! -f "$md_old_file" ]]; then
+            # New file detected, copy to .md.old
+            cp "$source_md" "$md_old_file"
+            log_info "New file detected. Copied '$source_md' to '$md_old_file'."
+            # Convert to HTML
+            convert_md_to_html "$md_old_file" &
+        else
+            # Compare the source .md with the existing .md.old
+            if ! diff -q "$source_md" "$md_old_file" &>/dev/null; then
+                # Files differ, update .md.old and reconvert
+                cp "$source_md" "$md_old_file"
+                log_info "Modified file detected. Updated '$md_old_file' with changes from '$source_md'."
+                # Convert to HTML
+                convert_md_to_html "$md_old_file" &
+            else
+                log_info "No changes detected for '$source_md'. Skipping conversion."
+            fi
+        fi
+    done
+
+    # Wait for all background conversions to finish
+    wait
+
+    log_success "Renaming and conversion of new or modified .md files completed."
+}
+
+# Function to handle deletions: Remove .html files corresponding to deleted .md files
+handle_deletions() {
+    log_info "Handling deletions of Markdown files..."
+
+    # Find all .md.old files in TEMP_DIR
+    find "$TEMP_DIR" -type f -name '*.md.old' | while IFS= read -r md_old_file; do
+        # Determine the corresponding .md file in SOURCE_DIR
+        source_md="$SOURCE_DIR/${md_old_file#$TEMP_DIR/}"
+        source_md="${source_md%.md.old}.md"
+
+        # Check if the source .md file exists
+        if [[ ! -f "$source_md" ]]; then
+            # Corresponding .md file has been deleted, remove the .html file
+            html_file="${md_old_file%.md.old}.html"
+            if [[ -f "$html_file" ]]; then
+                rm "$html_file"
+                log_success "Deleted '$html_file' as the source Markdown file no longer exists."
+                # Log the deletion
+                echo "$(date +"%Y-%m-%d %H:%M:%S") - Deleted '$html_file' due to source removal." >> "$LOG_FILE"
+            fi
+            # Remove the .md.old file itself
+            rm "$md_old_file"
+            log_info "Removed obsolete '$md_old_file'."
+        fi
+    done
+
+    log_success "Deletion handling completed."
+}
+
+# Function to generate index.html specifically
+generate_index() {
+    local index_md_old="$TEMP_DIR/index.md.old"
+    local index_html="$TEMP_DIR/index.html"
+
+    if [[ ! -f "$index_md_old" ]]; then
+        handle_error "'index.md.old' not found in '$TEMP_DIR'." "$EXIT_FAILURE"
+    fi
+
+    log_info "Generating 'index.html' from 'index.md.old'..."
+
+    # Convert the index.md.old file to HTML
+    convert_md_to_html "$index_md_old"
+
+    # Ensure index.html exists
+    if [[ ! -f "$index_html" ]]; then
+        handle_error "Failed to generate 'index.html'." "$EXIT_CONVERSION"
+    fi
+
+    log_success "'index.html' generation completed."
+}
+
+# Function to open index.html in qutebrowser
+open_browser() {
+    local index_file="$TEMP_DIR/index.html"
+    if [[ -f "$index_file" ]]; then
+        log_info "Opening '$index_file' in qutebrowser..."
+        qutebrowser "$index_file" &
+        log_success "Opened '$index_file' in qutebrowser."
+    else
+        handle_error "'$index_file' does not exist. Please ensure it is generated correctly." "$EXIT_FAILURE"
+    fi
+}
+
+# Function to display usage information
+usage() {
+    echo -e "${BOLD}Usage:${RESET} $0 [OPTIONS]"
+    echo ""
+    echo "Options:"
+    echo "  --index-wiki, -iw       Synchronize and convert Vimwiki to HTML, then open index.html in qutebrowser."
+    echo "  --help, -h              Display this help message."
+    echo "  --version, -V           Display the script's version."
+    echo ""
+    echo "Examples:"
+    echo "  $0 --index-wiki"
+    echo "  $0 -iw"
+    echo "  $0 --help"
+    echo "  $0 -h"
+    echo "  $0 --version"
+    echo "  $0 -V"
+}
+
+# Function to display version information
+version_info() {
+    echo -e "${BOLD}Vimwiki HTML Converter${RESET} version ${GREEN}$VERSION${RESET}"
+}
+
+# Function to update synchronization and conversion based on differences
+update_if_needed() {
+    # Synchronize new and updated files
+    synchronize_markdown
+    # Rename and convert new or modified .md files
+    rename_md_files
+    # Handle deletions
+    handle_deletions
+    # Generate index.html
+    generate_index
+}
+
+# ============================
+# Signal Handling Functions
+# ============================
+
+# Function to handle script termination gracefully
+cleanup() {
+    log_warning "Script interrupted. Cleaning up..."
+    # Terminate all background jobs
+    jobs -rp | xargs -r kill -TERM 2>/dev/null || true
+    exit "$EXIT_FAILURE"
+}
+
+# Trap SIGINT and SIGTERM signals
+trap cleanup SIGINT SIGTERM
+
+# ============================
+# convert_single_file Function
+# ============================
+convert_single_file() {
+    local md_file="$1"
+
+    # Validate filename
+    local filename
+    filename=$(basename "$md_file")
+    if ! is_valid_filename "$filename"; then
+        log_warning "Skipping file with invalid filename: '$md_file'"
+        return
+    fi
+
+    # Check if the file exists
+    if [[ ! -f "$md_file" ]]; then
+        handle_error "File '$md_file' does not exist." "$EXIT_FAILURE"
+    fi
+
+    # Copy the Markdown file to the temporary directory
+    local dest_dir="/tmp/markdowndump/"
+    mkdir -p "$dest_dir"
+    local dest_md_file="$dest_dir$filename"
+    cp "$md_file" "$dest_md_file"
+    log_info "Copied '$md_file' to '$dest_md_file'."
+
+    # Prepare the paths for HTML conversion
+    local html_file="${dest_md_file%.md}.html"
+    local temp_html_file="${html_file}.tmp"
+
+    # Extract the title for the HTML document
+    local title
+    title=$(extract_title "$dest_md_file")
+
+    # Convert Markdown to HTML using pandoc with CSS and metadata
+    if [[ -f "$CSS_FILE" ]]; then
+        if ! pandoc -f markdown -s --css="$CSS_FILE" --metadata title="$title" "$dest_md_file" -o "$temp_html_file"; then
+            handle_error "Failed to convert '$dest_md_file' to HTML." "$EXIT_CONVERSION"
+        fi
+    else
+        log_warning "CSS file '$CSS_FILE' not found. Skipping CSS for '$dest_md_file'."
+        if ! pandoc -f markdown -s --metadata title="$title" "$dest_md_file" -o "$temp_html_file"; then
+            handle_error "Failed to convert '$dest_md_file' to HTML." "$EXIT_CONVERSION"
+        fi
+    fi
+
+    # Move the temporary HTML file to the final destination
+    mv "$temp_html_file" "$html_file"
+    log_info "Converted Markdown file '$dest_md_file' to HTML '$html_file'."
+
+    # Open the HTML file in qutebrowser
+    qutebrowser "$html_file" &
+    log_success "Opened '$html_file' in qutebrowser."
+}
+
+# ============================
+# Main Script Execution
+# ============================
+
+main() {
+    # Parse command-line arguments
+    if [[ $# -eq 0 ]]; then
+        log_error "No arguments provided. Use --help for usage information."
+        exit "$EXIT_FAILURE"
+    fi
+
+    while [[ $# -gt 0 ]]; do
+        case "$1" in
+            --index-wiki|-iw)
+                action="index_wiki"
+                shift
+                ;;
+            --convert|-c)
+                if [[ -z "${2:-}" ]]; then
+                    echo -e "${RED}[ERROR]${RESET} --convert flag requires a filename argument."
+                    exit "$EXIT_FAILURE"
+                fi
+                convert_single_file "$2"
+                exit "$EXIT_SUCCESS"
+                ;;
+            --help)
+                usage
+                exit "$EXIT_SUCCESS"
+                ;;
+            -h)
+                usage
+                exit "$EXIT_SUCCESS"
+                ;;
+            --version)
+                version_info
+                exit "$EXIT_SUCCESS"
+                ;;
+            -V)
+                version_info
+                exit "$EXIT_SUCCESS"
+                ;;
+            *)
+                log_error "Unknown option: $1. Use --help for usage information."
+                exit "$EXIT_FAILURE"
+                ;;
+        esac
+    done
+
+    # Execute based on the action
+    case "$action" in
+        index_wiki)
+            check_bash
+            check_dependencies
+            validate_paths
+            # Create TEMP_DIR if it doesn't exist
+            if [[ ! -d "$TEMP_DIR" ]]; then
+                log_info "Temporary directory '$TEMP_DIR' does not exist. Creating and performing full synchronization."
+                mkdir -p "$TEMP_DIR"
+                synchronize_markdown
+                rename_md_files
+                handle_deletions
+                generate_index
+            else
+                log_info "Temporary directory '$TEMP_DIR' already exists. Checking for updates."
+                update_if_needed
+            fi
+            open_browser
+            log_success "All tasks completed successfully."
+            exit "$EXIT_SUCCESS"
+            ;;
+        *)
+            # This should not happen due to earlier checks
+            log_error "Invalid action." "$EXIT_FAILURE"
+            ;;
+    esac
+}
+
+# Invoke the main function
+main "$@"
+